There is a [`style-check`](style-check/) tool which is run in CI to check some of these. To use it locally, run `cargo run --manifest-path=style-check/Cargo.toml src`.
* Use reference links, with shortcuts if appropriate.
Place the sorted link reference definitions at the bottom of the file, or at the bottom of a section if there is an unusually large number of links that are specific to the section.
* Links should be relative with the `.md` extension.
Links to other rust-lang books that are published with the reference or the standard library API should also be relative so that the linkchecker can validate them.
* See the [Conventions] section for formatting callouts such as notes, edition differences, and warnings.
Usually this is only necessary when the testing framework does not support it (such as external crates or modules, or a proc-macro), or it contains pseudo-code which is not valid Rust.
* Whenever there is a difference between editions, the differences should be called out with an "Edition Differences" block.
The main text should stick to what is common between the editions.
However, for large differences (such as "async"), the main text may contain edition-specific content as long as it is made clear which editions it applies to.